CVE-2022-50400
📋 TL;DR
This CVE describes a memory leak and potential debugfs corruption vulnerability in the Linux kernel's greybus audio_helper module. The flawed debugfs logic could leak memory or incorrectly remove debugfs entries, potentially affecting system stability. Systems running vulnerable Linux kernel versions with greybus audio functionality are affected.
💻 Affected Systems
- Linux kernel with greybus audio_helper module
📦 What is this software?
Linux Kernel by Linux
The Linux Kernel is the core component of the Linux operating system, serving as the critical interface between computer hardware and software processes. As the heart of millions of servers, cloud infrastructure, embedded systems, Android devices, and IoT deployments worldwide, the Linux Kernel mana...
Learn more about Linux Kernel →Linux Kernel by Linux
The Linux Kernel is the core component of the Linux operating system, serving as the critical interface between computer hardware and software processes. As the heart of millions of servers, cloud infrastructure, embedded systems, Android devices, and IoT deployments worldwide, the Linux Kernel mana...
Learn more about Linux Kernel →Linux Kernel by Linux
The Linux Kernel is the core component of the Linux operating system, serving as the critical interface between computer hardware and software processes. As the heart of millions of servers, cloud infrastructure, embedded systems, Android devices, and IoT deployments worldwide, the Linux Kernel mana...
Learn more about Linux Kernel →Linux Kernel by Linux
The Linux Kernel is the core component of the Linux operating system, serving as the critical interface between computer hardware and software processes. As the heart of millions of servers, cloud infrastructure, embedded systems, Android devices, and IoT deployments worldwide, the Linux Kernel mana...
Learn more about Linux Kernel →⚠️ Risk & Real-World Impact
Worst Case
System instability or denial of service due to memory exhaustion or debugfs corruption affecting multiple subsystems
Likely Case
Memory leak causing gradual performance degradation or system instability over time
If Mitigated
Minimal impact if system doesn't use greybus audio functionality or has limited debugfs usage
🎯 Exploit Status
Requires local access and specific conditions to trigger the debugfs logic
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Kernel versions with commits 4dab0d27a4211a27135a6899d6c737e6e0759a11 or later
Vendor Advisory: https://git.kernel.org/stable/c/4dab0d27a4211a27135a6899d6c737e6e0759a11
Restart Required: No
Instructions:
1. Update Linux kernel to patched version 2. Rebuild kernel if using custom build 3. Load updated kernel module
🔧 Temporary Workarounds
Disable greybus audio module
allPrevent loading of vulnerable greybus audio_helper module
echo 'blacklist gb-audio' >> /etc/modprobe.d/blacklist.conf
rmmod gb-audio
🧯 If You Can't Patch
- Disable greybus audio functionality if not needed
- Monitor system memory usage for unusual patterns
🔍 How to Verify
Check if Vulnerable:
Check if greybus audio module is loaded: lsmod | grep gb-audio AND check kernel version against vulnerable rangesCheck Version:
uname -rVerify Fix Applied:
Verify kernel version includes fix commit: grep -q '4dab0d27a4211a27135a6899d6c737e6e0759a11' /proc/version_signature📡 Detection & Monitoring
Log Indicators:
- Kernel oops messages
- Memory allocation failures
- Debugfs related errors
Network Indicators:
- None - local vulnerability only
SIEM Query:
Search for kernel panic or oops messages containing 'greybus' or 'audio_helper'🔗 References
- https://git.kernel.org/stable/c/4dab0d27a4211a27135a6899d6c737e6e0759a11
- https://git.kernel.org/stable/c/5699afbff1fa2972722e863906c0320d55dd4d58
- https://git.kernel.org/stable/c/d0febad83e29d85bb66e4f5cac0115b022403338
- https://git.kernel.org/stable/c/d517cdeb904ddc0cbebcc959d43596426cac40b0
- https://git.kernel.org/stable/c/d835fa49d9589a780ff0d001bb7e6323238a4afb
